An Improved Two-Step M Estimation Method Based on the Danish Method
1〓Guangxi Scientific Experiment Center of Mining, Metallurgy and Environment, 12 Jiangan Road,Guilin 541004, China
2〓College of Geomatic Engineering and Geoinformatics, Guilin University of Technology, 12 Jiangan Road ,Guilin 541004, China
3〓Guangxi Key Laboratory of Spatial Information and Geomatics, 12 Jiangan Road ,Guilin 541004, China
Abstract To deal with the problem of improper selection of initial and critical values in robust estimation methods, an improved two-step M estimation method is proposed, based on the L1 estimation value and modified weight function of the Danish method.The proposed method is not only relatively robust, but also optimizes the least squares.The numerical experiments show that the estimated results of this method are basically consistent with those of LS estimation when there are no gross errors, and the method with conspicuous robust effect is much better than traditional other two-step robust estimation methods.